1. Field of the Invention
The present invention relates to a power-supplying member and a heating apparatus using the same, suitable for semiconductor manufacturing systems such as thermal Chemical Vapor Deposition (CVD) systems and plasma CVD systems.
2. Description of the Related Art
There is conventionally known, as disclosed in Japanese Patent Application Laid-Open No. H5-326112, heating apparatuses (hereinafter referred to as “ceramic heaters”) comprise a ceramic base in which a heating resistor or an electrode are embedded; a tubular supporting member which supports the ceramic base; and a power-supplying member which is disposed to a hollowed part in the tubular supporting member, and which supplies power to the heating resistor or the electrode. According to the ceramic heaters of the related art, an end of the power-supplying member formed from a nickel or a nickel-base alloy is connected to the heating resistor or the electrode, and the other end of the power-supplying member is connected to the power supply through the connector or the like.
On the other end of power-supplying member, an o-ring made of heat-resistant fluororubber is used to hold the power-supplying member. Also, on the other end of the power-supplying member, a connector for holding the power-supplying member is made of copper or beryllium copper because the connector has to possess spring properties. Since the O-ring and the connector withstand temperatures of up to 200[° C.], the other end of the power-supplying member must be kept at or below the heat resistance temperature of the O-ring and the connector. For this reason, the other end of the power-supplying member is kept in low-temperature conditions as compared to one end of the power-supplying member on the ceramic base side, due to heat transfer of the gas around the power-supplying member, heat radiation to the supporting member, and the heat conduction to the cooling shaft fixing the other end of the power-supplying member.
However, when there is a low-pressure atmosphere close to a vacuum around the other end of the power-supplying member or there is a low gas pressure atmosphere close to a vacuum around the other end of the power-supplying member, less gas conduction occurs around the other end of the power-supplying member. Consequently, the temperature of the other end of the power-supplying member does not exhibit a significant drop, as compared to the temperature of the ceramic base side. This results in causing damage to the O-ring, thus making it impossible for the O-ring to hermetically seal and hold the hollow of the supporting member and the chamber. The problem of the temperature also leads to the problem of degrading the spring properties of the connector. This results in arcing occurring between the power-supplying member and the connector, thereby causing damage to the apparatus.
It is an object of the present invention to provide a power-supplying member that can improve durability of a heating apparatus and a heating apparatus using the same.